Problem: Solve for $r$, $- \dfrac{r - 1}{2r - 7} = \dfrac{1}{6} $
Multiply both sides of the equation by $2r - 7$ $ -(r - 1) = \dfrac{2r - 7}{6} $ Multiply both sides of the equation by $6$ $ -6(r - 1) = 2r - 7 $ $-6r + 6 = 2r - 7$ $6 = 8r - 7$ $13 = 8r$ $8r = 13$ $r = \dfrac{13}{8}$